Light sources are often controlled by light switches containing dimmer circuitry that allows users of the light switch to control the brightness emitted by the light source. The light sources controlled by the light switches are typically incandescent or halogen bulbs, however new light emitting sources have recently been introduced. For example, LED lights are now available as an alternative to incandescent and halogen lighting sources. LED lights are more energy efficient than incandescent or halogen bulbs.
The dimmer circuits used with incandescent and halogen bulbs control the brightness of the light sources by varying the power transmitted to the bulb. Incandescent and halogen bulbs are passive elements and present a resistive load to the dimmer. However, LED lights do not present a resistive load to the dimmer. Consequently, LED lights do not function as expected when dimmed via a conventional dimmer circuit.